Thermochemical Characterization and Caloric Value Prediction of Sugarcane Bagasse, Rice Husk and Coffee Husk Biomass

The use of agro-industrial waste as an alternative energy source contributes significantly to the reduction of greenhouse gas emissions. In this study, the higher heating value (HHV) of sugarcane bagasse, rice husk, and coffee husk was determined by validating eight predictive equations. Combustion parameters (fuel ratio, combustibility index, and volatile flammability) and gaseous emission factors (CO, CO2, CH4, NO., SO2) were calculated. Coffee husks shown the highest HHV (18.51 MJ/kg) and carbon content (54.04 %), followed by sugarcane bagasse (17.81 MJ/kg) and rice husks (15.40 MJ/kg). The fuel ratio ranged from 0.16 to 0.20, well below the critical threshold of 2.0, ensuring excellent ignition. The flammability index (108–119 MJ/kg) significantly exceeded the recommended minimum value of 23 MJ/kg. SO2 emissions were negligible due to the low sulfur content (< 0.005 kg/ton). Model validation revealed that model 5 exhibited the highest prediction accuracy (R² = 0.984, RMSE = 0.169 MJ/kg), followed by model 4 (R² = 0.965, RMSE = 0.249 MJ/kg). All three residues showed favorable properties for thermochemical conversion, with model 5 being the most suitable for estimating the calorific value of agro-industrial waste.